So the 3d printer I have constructed has a minor, correctable design flaw. The part cooling fan cools the just laid plastic so that it sticks to the existing printed part.
In my Prusa Mk2 the part cooling fan only pushing air from the front to the back, a single direction. This means there is a wind shadow behind the extruder nozzle. 3 out of 4 ain't bad, but one direction of printing prints less well.
People years ahead of me have fixed this problem with improved fan shrouds that blow air from the left and right, avoiding any shadow and improving 1/4 of the print lines.
This part is probably the one I want to print, it has room for an insulating silicone sock that I have fitted.
This part probably doesn't fit, but is smaller and probably prettier.
This part doesn't solve the wind shadow problem but it tilts the fan for improved power, an improvement that was taken into the design of the Prusa Mk3.
My problem is that I need to print this part in ABS plastic. My new printer can get hot enough to do this, that isn't a problem. This kind of plastic won't melt/ warp/ drool being next to the hot print head. I can't use regular PLA or PETG here, they are easier to print but they won't work for very long, the part would fail.
ABS (Acrylonitrile Butadiene Styrene) should be printed without a fan running but my problem is that my fan is connected to a permanently on fan port at the moment, due to my ignorance.
I have one controllable fan port on my little motherboard, but I'm not sure how it is configured in the firmware. Could be my an extruder cooling fan, could be a ventilation fan, or maybe the one I want!! Time to test!!